Thursday, July 1, 2010

Of Cats and Kidneys

Lately at work, it's been nothing but kidneys kidneys kidneys. Granted, it's the most common illness we see in older cats.

A Japanese client brought in her little kitty because it had lost some weight and had stopped eating. I kinda knew when I was examining the cat that it was going to be severe renal failure. The cat's body temperature was low, and it had very foul smelling breath. Not the kind of bad dental-disease breath that I commonly encounter. This was the something-died-inside-this-cat's-mouth smell that means one thing: uremia, i.e. very high level of toxins in the bloodstream. Many of these cats have ulcers in their mouth as a result of the uremia (we call them, fittingly, "uremic ulcers"), and this cat certainly did. Strangely, a week later, I get another Japanese client, with another cat who's not eating, and it turns out to be severe uremia and oral ulcers. The first cat didn't respond so well to treatment. The second cat was hospitalized at our clinic, and at the time, it wasn't doing very well either. The levels were simply too high. But you never know until you try.

The most interesting case, and pretty gratifying for me, is the case I did not see. It was a busy day, but amazingly, I had a nice, clear 45 minute break in the middle of it all. I was eating my sandwich, looking at my messages, and there's a message from a guy who is not a client at our hospital, but he was calling for advice about his cat who had a seizure and was told the cat had kidney failure. I was intrigued, since you don't often see seizures with kidney failure. I called him at home and he told me that he had brought his cat into a local vet hospital (he's in the West Village, here in NYC), because his cat had a seizure. The vet did some bloodwork and told him that the cat had kidney disease. He obtained a copy of the bloodwork and read me the numbers. They were frighteningly high. The BUN and creatinine (the two major parameters we use to assess kidney function) were through the roof. I asked about phosphorus. He read me the number and it, too, was super-elevated. I asked about potassium. Here's where it gets interesting. I was expecting it to be normal or low, but the number he told me was actually a little high. Typically, if a cat with chronic renal failure is going to have a potassium abnormality, it's going to be a low potassium, because they are urinating so much that their kidneys can't conserve it. A high potassium is weird. Unless... this isn't chronic renal failure. On further questioning, I asked if his cat has been ill for a while, but he said no, that the cat was perfectly fine the day before. I asked if the cat was making urine adequately lately. He said no. He said that she was going into her litter box, and squatting in the corner of the box, like she usually does, but she wasn't producing any urine.

Uh oh.

I told him that I thought his cat had acute renal failure. This is very different from chronic renal failure. Acute renal failure (ARF), as the name implies, is a sudden decrease in kidney function. The kidneys start to shut down, and they stop producing urine. The kidney toxin levels start to rise, including the potassium. Potassium, if it does not get out of the body fairly quickly, will build up and cause severe cardiac disturbances. I told this guy that he needed to get his cat to an emergency clinic immediately. I sent him to NYC Veterinary Specialists (I think they're great). He was upset that his veterinarian didn't emphasize the gravity of the situation, but was grateful that he got to speak to me. I'm lucky that I had, amazingly, a break in my day.

Later that evening, I called the emergency clinic to see if the cat arrived and how she was doing. She did arrive, and although her kidney numbers were extremely high, the numbers were starting to come down, and she had begun to produce urine. I have to say, to be able to help a cat with a simple phone call is one of the great perks of my job.

Dr. Arnold Plotnick (MS, DVM, ACVIM) blogs about professional and personal life experiences as an expert in the field of feline veterinary medicine.

Dr. Arnold Plotnick is a board-certified veterinary internist, feline expert, and the founder of Manhattan Cat Specialists. In addition to his medical work, he is an award-winning veterinary medicine writer.